When placing wireless communication devices that use different frequencies for transmission and reception, wireless frequencies for transmission and reception need to be uniquely determined so as to establish wireless communication among the devices.
When placing the wireless communication devices, a worker had to check a radio wave status between the devices to be newly provided in advance, derive wireless frequencies for transmission and reception, which are estimated to be idler frequencies, and perform setting with respect to the wireless communication devices. In addition, there was not always guarantee that the wireless communication is established by the estimated frequencies, and in some cases, workers had to communicate with each other to perform readjustment, for example, using other frequencies.
FIG. 1 illustrates an image example when newly placing wireless communication devices.
It is assumed that already-placed wireless communication devices (11-1, 11-2, 12-1, 12-2) achieve wireless connections among the devices at respective wireless frequencies (F3, F4, F5, F6). It is to be noted that F3 and F4, and, F5 and F6 are frequencies different from each other. For example, the wireless communication device 11-1 transmits wireless data at the frequency F3 and receives wireless data at the frequency F4.
When newly placing wireless communication devices (10-1, 10-2) in this region, a worker seeks a choice of frequencies unaffected by the radio waves (F3, F4, F5, F6) flying around. After that, the worker finds the choice of frequencies (for example, F1, F1′, F2, F2′), and uniquely determines frequencies to be used among these while performing setting of frequencies with respect to the wireless communication devices (10-1, 10-2) and verifying whether wireless communication is established or not between the actual devices. It is to be noted that the respective wireless communication devices need not be placed as in FIG. 1, and may be placed so as to be able to communicate with one another.
As described above, in order to determine frequencies for transmission and reception among wireless communication devices to be newly placed, hand working by a worker was required, and working man-hours and cost were high.
For the foregoing problem, PTL 1 discloses a wireless communication system capable of suppressing crosstalk and selecting an appropriate frequency in a short time.
In PTL 1, by using information of positions of radios to be placed and a frequency resource table including a plurality of frequencies that can be used for wireless communication and information of positions where the respective frequencies are used, a frequency to be used for the wireless communication between the radios is determined.
In addition, an automatic setting method and an automatic setting system for a wireless frequency of PTL 2 and 3 disclose an automatic setting method and an automatic setting system for a wireless frequency, which can easily and automatically determine and set a wireless frequency of a newly-placed wireless communication line.
In PTL 2 and 3, for frequencies that can be used in a wireless line, by using a wireless communication device data table including, for each wireless frequency, values of the wireless frequency and an ID of a wireless communication device using the wireless frequency, a wireless frequency of a newly-placed wireless line is determined.